XML 74 R60.htm IDEA: XBRL DOCUMENT v3.3.1.900

Note 2 - Business Combination (Details) - Pro Forma Information - Firstbank Corporation [Member]	12 Months Ended
	Dec. 31, 2014 USD ($) $ / shares
Note 2 - Business Combination (Details) - Pro Forma Information [Line Items]
Net interest income	$ 98,607,000
Noninterest expense	81,295,000
Net income	$ 22,659,000
Net income per diluted share (in Dollars per share) | $ / shares	$ 1.33

X

- Definition

The pro forma net interest Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

No definition available.

+ Details

Name:	mbwm_BusinessAcquisitionsProFormaNetInterestIncome
Namespace Prefix:	mbwm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The pro forma noninterest expense for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

No definition available.

+ Details

Name:	mbwm_BusinessAcquisitionsProFormaNoninterestExpense
Namespace Prefix:	mbwm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	mbwm_Note2BusinessCombinationDetailsProFormaInformationLineItems
Namespace Prefix:	mbwm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	us-gaap_BusinessAcquisitionAxis=mbwm_FirstbankCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: